DE4326772A1 - Reaction products from olefinically unsaturated carboxylic acids and polyetherols and their use as demulsifiers for crude oil emulsions - Google Patents

Description

The present invention relates to reaction products olefinically unsaturated carboxylic acids and polyetherols Lich through

• A) condensation of one or more unsaturated C₃-C₁₀ carboxylic acids or their derivatives of the general formula I. in which R¹ and R² are hydrogen, C₁-C₄-alkyl or carboxyl and R³ is hydrogen or methyl, and R¹ can form a 5- or 6-membered anhydride ring with the carboxyl group,
  with a polyetherol of the general formula II in the
  R⁴ for the remainder of a mono- or polyhydric alcohol, phenol or an alkylphenol with 7 to 30 carbon atoms, the remainder of an alkylphenol / formaldehyde or alkylphenol / acetaldehyde condensation product,
  R⁵ for a branched or straight-chain C₂-C₄-alkylene group, wherein ver different units [R⁵-O] may be present within a polyalkylene oxide chain, and
  x represents an integer from 5 to 120,
  in the molar ratio of the compounds II to I from 2: 1 to 10: 1 and in the weight ratio from 25: 1 to 1000: 1,
• B) Polymerization of the condensation product thus obtained with one or more unsaturated carboxylic acids I and counter optionally other olefinically unsaturated, with the carbon acids I copolymerizable monomers, the proportion of Carboxylic acids I in the amount of olefinically unsaturated Mo nomeren is 50 to 100 mol%, and the molar Ratio of polyetherol II to the sum of those in the Process steps A) and B) used olefinically unsaturated monomers is 1: 5 to 1: 200, as well as closing
• C) condensation of the reaction mixture thus obtained with the Provided that not all hydroxyl groups are implemented.

The invention also relates to the preparation of this reaction products and mixtures containing the reaction products. Finally, the invention relates to the use of the reaction products as demulsifiers for crude oil emulsions.

When crude oil is extracted, the Deposits with an increasing proportion of water. In emulsify the surface-active substances contained in the crude oils most of the water, with stable water-in-oil Form emulsions. Salts can be dissolved in the emulsion water. that in the processing of crude oil in the refinery Cause corrosion problems. There are also high levels of water in the raw Oil at increased transportation costs between the oil field and the refinery. The emulsion water must therefore be separated off before transport or be lowered below an acceptable concentration. this happens mostly through the addition of petroleum emulsion splitters (also demulga called gates), with heating of the crude oil separating relieved and accelerated.

Crude oils differ depending on their provinces strong in their composition. The contained in the crude oils natural emulsifiers have different relatively compli adorned chemical structures and compositions, so that to overcome their effect selectively petroleum emulsion splitters (Demulsifiers) must be developed. By opening up new crude oil fields as well as changed production conditions at äl In new fields, new demulsifiers are constantly needed faster separation in water and oil and as low as possible Residual water and associated residual salt amounts.

So-called "polymeric petroleum emulsions" are known as demulsifiers splitter ", including polymers with a carbon main chain understood. According to the patent specification CA 10 10 740 in alkoxylated alcohols and alkoxylated alkylphenol formaldehyde resins by etherification with unsaturated diglycidyl compounds (e.g. glycidyl acrylate) by esterification with maleic anhydride or unsaturated acids or by transesterification with esters saturated acids unsaturated, radically polymerizable radio tions introduced, which in a subsequent reaction with other monomers in defined proportions in solution be polymerized.

In DE-C 33 38 923 products are described which consist of a Copolymerization of polyoxyalkylene ethers of allyl or meth allyl alcohol with vinyl esters or acrylic acid or methacrylic acid esters can be obtained. All of these products are effective specific or manufacturing-related weaknesses. So it happens Use of glycidyl compounds to introduce the unsaturated functions in the polymerization often to bil formation of gel bodies and inhomogeneities in derivatives of Ally alcohol, methallyl alcohol and maleic acid result poor copolymerization conditions. Furthermore it comes often to gelation and solidification reactions, in particular by using multifunctional starting alcohols at the Alkoxylation.

In US-A 4 626 379 demulsifiers are described which by partial condensation of the reaction product of a mixture of at least two alkoxylated compounds with a vinyl Monomer can be produced. There is at least one of the alkoxylated compounds made from a block copolymer by polyaddition of a polyoxyalkylene glycol with a Diglycidyl ether. The synthesis described here is complex and The diepoxides used are relatively expensive as raw materials siv.

DE-A 36 35 489 describes copolymers of hydrophobic acrylic acid or methacrylic acid esters and hydrophilic monomers. The The hydrophobic esters are produced by acidic catalyze azeotropic esterification of alkoxylates mono- or polyvalent ger alcohols or alkylphenol / aldehyde condensation products with (Meth) acrylic acid. After the copolymerization of the hydrophobic esters with free hydrophilic monomers transferred a no longer reactive form and / or the catalyst acid neutralized with a tertiary amine. The production of these products is time-consuming because the esterification of the Alkoxylates with (meth) acrylic acid take several hours  takes. In the esterification of alkoxylates of polyhydric alcohols it is not possible to selectively produce the monoester, so that it by the existing multifunctional acrylates in the Copolymerization with hydrophilic monomers easily to form and soluble gels is coming.

DE-A 41 04 610 describes polymeric emulsion splitters ben obtained by polymerizing vinyl monomers rer in the presence of alkoxylates based on mono- or polyvalent Alcohols and subsequent condensation reaction. Here you have to the vinyl monomers carry suitable reactive groups, wel che can react with the OH functions of the alkoxylates nen. In practice it has been shown that both are highly effective speed as well as the producibility of these implementation products sensitive to small quality differences of the used Suspend alkoxilates. Reproducible product properties are therefore only to be achieved with great technical effort.

The object of the present invention was to use demulsifiers for ver to provide the fastest possible separation of Emulsions in water and oil and the lowest possible residual water deliver quantities, are stable in storage, simple and above all without larger quality fluctuations can be reproducibly produced.

Accordingly, the reaction products defined at the outset were found the. Furthermore, a method for producing this reak tion products found as well as mixtures of this compound and the use of the reaction products and their Mixtures as demulsifiers for crude oil emulsions.

As vinyl unsaturated C₃-C₁₀ carboxylic acids or their Derivatives I are acrylic acid, methacrylic acid, maleic acid, fumar acid and maleic anhydride to name, of which acrylic acid be is preferred.

The monomers I can be used alone or in process step B) Comonomers are polymerized. Aliphati come as comonomers cal esters of carboxylic acids I such as methyl (meth) acrylate, Ethyl (meth) acrylate, isobutyl methacrylate and lauryl acrylate as well considered as C₁-C₂₀ hydroxy esters of carboxylic acids I as Hydroxyethyl (meth) acrylate and amides and C₂-C₄₀ dialkylamides Carboxylic acids I such as acrylamide and such amides, the others functional groups carry like 2-acrylamido-2-methylpropane sulfonic acid. Furthermore, C₈-C₁₂ aryl vinyl compounds are like Styrene, C₃-C₁₀ alkenes such as isobutene, trimethylpentene, unsaturated C₃-C₈ alcohols such as allyl alcohol, vinyl esters of C₂-C₁₀ carbon  acids such as vinyl acetate and vinyl propionet and C₃-C₂₀ alkyl vinyl to name ethers such as vinyl methyl ether as comonomers.

There are also heterocyclic vinyl compounds such as vinyl imidazole and vinyl pyrrolidone.

The polyetherols of formula II to be used according to the invention are known per se or can be produced by known methods.

The polyetherols can be prepared (see e.g. DE-A 36 35 489, S. 5) by implementing a mono- or multifunctional Alko hauls with an alkoxide or a mixture of several alkoxides or in blocks with several alkoxides with the help of basi shear catalysts such as sodium hydroxide at temperatures of 80 up to 160 ° C. The ratio of alcohol to alkoxides can the production vary widely, but is expediently in Range from 1: 120 to 1: 5. Preferred alkoxides are Ethylene oxide, propylene oxide and 1,2-butylene oxide or their Mixtures. As alcohols come preferably C₁-C₃₀-alkanols in Be traditional, z. As ethanol, butanol, isopropanol, tallow fatty alcohol and Stearyl alcohol. C₂-C₃₀ polyalcohols should also be mentioned: Ethylene glycol, bisphenol A, glycerin, trimethylolpropane, penta erythritol, sorbitol and polyglycerin.

Alkylphenols of the general formula III also come in Be costume:

where R⁶ z. B. methyl, iso-propyl, tert-butyl, hexyl or nonyl and the alkylphenol / formaldehyde or Acetaldehyde condensation products.

Alkoxylated alkylphenol / formaldehyde or acetaldehyde condensation products

The alkylphenyl / For used as alcohols for alkoxylation Maldehyde or acetaldehyde resins are known per se Way by reacting the aldehyde with the alkylphenol in the Ratio 2: 1 to 1: 2 under base or acid catalysis at Tempe temperatures of 80 to 250 ° C with the help of a high-boiling Solvent for complete azeotropic removal of the formed reaction water. As alkylphenols e.g. B. nonylphenol, t-butylphenol or octylphenol used. When  The catalyst generally becomes an alkyl sulfonic acid or alkyl benzenesulfonic acid, e.g. B. Dodecylbenzenesulfonic acid used.

Generally the molecules contain 4 to 12 aromatic nuclei, preferably 5 to 9.

The condensation products thus obtained are given as above alkoxylated.

Process step A

The carboxylic acids or carboxylic acid derivatives I are in the presence a molar excess of polyetherol II condenses, d. H. the acid or anhydride groups are esterified. The Compounds II and I are in a molar ratio of 2: 1 to 10: 1, the weight ratio being 25: 1 to 1000: 1. The reaction can be carried out in the presence of an acidic catalyst such as a lactic acid or an organic acid such as para-toluenesul fonic acid, the amount of catalyst generally 0.5 up to 4% by weight, based on the amount of polyetherol II. As a rule, the condensation is carried out in an inert solvent carried out. Aromatic hydrocarbons come as solvents substances such as toluene and xylene as well as commercially available, high-boiling Aromatic mixtures into consideration, but also decalin. The amount of Solvent is generally 20 to 80 wt .-% based on the overall approach. The reaction can take place at temperatures of 60 up to 200 ° C for 0.5 to 3 hours. On a separation of the water formed in the process can generally be dispensed with.

Process step B

The reaction mixture obtained after process step A), which in essentially the condensation product as well as unreacted Containing polyetherol II is used for polymerization with other added olefinically unsaturated monomers, the molar Ratio of polyetherol II to the sum of those in the process steps A) and B) used olefinically unsaturated monomers ren is 1: 5 to 1: 200, preferably 1:10 to 1:50. The amount of carboxylic acids I in the amount of in this process step converted olefinically unsaturated monomers is 50 to 100 mol%, preferably 75 to 100 mol%.

The polymerization is carried out according to the known discontinuous or continuous process of radical polymerization such as bulk, suspension, precipitation or solution polymerization and Initiation with conventional radical donors such as dicyclohexylperoxi dicarbonate, tert-butyl peroctoate, tert-butyl perpivalate,  2,2'-azobis (isobutyronitrile), dicumyl peroxide, di-tert-amyl pero xid, di-tert-butyl peroxide, cumene hydroperoxide or tert-butyl hy droperoxide and mixtures carried out with each other. Generally mean these initiators in amounts of 0.1 to 20 wt .-%, preferably 0.2 to 15% by weight, based on the monomers set.

The polymerization usually takes place at temperatures of 40 up to 200 ° C, preferably 60 to 150 ° C, within 0.5 to 10 h, preferably 1 to 6 h, particularly preferably 2 to 4 h, with Use of solvents with boiling temperatures below the Polymerization temperature is advantageously carried out under pressure. The polymerization is expediently in the absence of air, i. i.e. if cannot be worked under boiling conditions, e.g. More colorful Nitrogen or carbon dioxide is carried out because oxygen is the Po lymerisation delayed. By using redox coinitiato ren such as benzoin, dimethylaniline, ascorbic acid and organic soluble complexes of chromium can accelerate the reaction the. The amounts usually used are 0.1 to 2000 ppm by weight, preferably 0.1 to 1000 ppm by weight.

It is often useful to achieve low molecular weight copolymers moderate to work in the presence of regulators. Suitable regulators are, for example, allyl alcohols, such as buten-1-ol-3, organic Mercapto compounds such as 2-mercaptoethanol, 2-mercaptopropanol, Mercaptoacetic acid, mercaptopropionic acid, tert-butyl mercaptan, n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan and ter.- Dodecyl mercaptan, generally in amounts from 0.1 to 10 wt .-% are used.

Suitable apparatus for the polymerization are e.g. B. usual Mixing kettle with, for example, anchor, blade, impeller or Multi-stage impulse countercurrent stirrer and for continuous Manufacture of stirred tank cascades, tubular reactors and static mixers shear.

A simple method for producing the poly according to the invention merisate is solution polymerization. It is in solution carried out in which the monomers and the formed Copolymers are soluble. There are all solvents for this suitable that meet this requirement and that with the monomers do not respond.

For example, these are aromatic and alkyl-substituted aro matic hydrocarbons such as toluene, xylene, ethylbenzene, Cumene, high-boiling aromatic mixtures such as B. Solvesso® 100, 150 and 200, aliphatic and cycloaliphatic hydrocarbons  such as B. n-hexane, cyclohexane, methylcyclohexane, n-octane, iso-oc tan, decalin, paraffin oils, Shellsol® TD, T and K and acetone, Cyclohexanone, tetrahydrofuran and dioxane, being used to achieve low molecular weight copolymer tetrahydrofuran and dioxane are well suited.

Since the demulsifiers for crude oil emulsions are surface-active sub are punched in the continuous phase (oil phase) of the Crude oil emulsion should be soluble, it is appropriate to a To choose solvent for the polymerization, which with the Emul sion is compatible, so that the demulsifier solution of the emulsion can be added directly. Solution polymerization is that preferred production form for the copolymers according to the invention sate.

When carrying out the solution polymerization, it is advisable to to submit the reaction mixture from process step (A) and the Monomers with the initiator and optionally coinitiator, Reg Meter in solvent and solvent. The monomers can too individually and at different speeds the. This is recommended for monomers with very different cher reactivity and if a particularly even distribution of the less reactive monomer is desired. It will less reactive monomer faster and the more reactive monomer metered in more slowly. It is also possible to use the entire amount of one Voromers, preferably the less reactive monomer and only add the more reactive. After all, it is possible to present all components and only the initiator and if necessary, add the coinitiator and controller ("batch" risk wise). When carrying out this driving style on a larger scale However, problems with heat dissipation can occur, so that this way of driving only at low concentrations of too polymeri based monomers should be used.

Process step C

After the polymerization, the reaction gene thus obtained is subjected to a condensation mixture.

In this step, part of the free hydroxyl groups of the polyetherol with some of the reactive groups of the Polymer from the vinyl monomers (e.g. acrylic acid or their esters) implemented. This leads to bridging where be formed by very effective demulsifiers. The together settlement of the polyetherol, the vinyl monomers and the react tion conditions must be chosen so that complete oil-soluble end products are obtained. In the condensation step  Therefore, not all hydroxyl groups of the alkoxylate are allowed to be set, whereby insoluble products would form, rather, low sales are usually sufficient to achieve the desired effect to achieve. Such process products have been found in particular proven with regard to their use as demulsifiers, their Acid number after the condensation is 70 to 100, the Hydroxyl number is 2 to 20 and their K value (after H. Fikentscher, Cellulosechemie Band 13, pages 58 to 64, and 71 to 74 (1932), determined in 2% xylene solution) 10 to 50, is preferably 14 to 30.

The preferred reaction in the condensation step is Ver esterification.

The condensation is usually at temperatures between 80 and 250 ° C, preferably 100 to 200 ° C and particularly preferably between 120 and 180 ° C within 0.5 to 10 hours, preferably 1 to 8 hours and particularly preferably 2 to 6 hours in the Melt or carried out in solution. Is the boiling point of the solvent below the desired condensation temperature rature, the condensation is carried out under pressure.

The reaction mixture is used to carry out the condensation step from process step B) to the desired temperature brings. In some cases it is useful to use low molecular weight Re action products (e.g. water or low molecular weight alcohols) to remove the reaction vessel. This can e.g. B. done by that one passes an inert gas over the polymer melt or by using an entrainer. Should z. B. water from the Reaction mixture are removed, are suitable as entrainer the usual organic azeotropes with water Solvents, especially xylene or toluene. The condensation can, especially by adding catalysts Catalysts such as mineral acids, e.g. B. sulfuric acid and salt acid, sulfonic acids such as p-toluenesulfonic acid, dodecylbenzenesulfone acid or acidic ion exchangers are accelerated. Will Ka Talysatorsäure added, this can be done at the end of Kon neutralization step. Prinzi are suitable for this piell all basic compounds. However, preferably Amines such as triethylamine, ethylhexylamine, tributylamine, morpholine, Piperidine or ethanolamine used. At least the necessary to neutralize the catalyst acid, stoichiometric Amount of base used. But it can also be a larger base amount be added. In this case, the partial or complete neutralization of the rest of the vinyl Monomeric acid groups, especially carboxyl groups derived from carboxylic acid I. By the right one  Choice of base and degree of neutralization can affect effectiveness of the demulsifiers are adapted to the crude oil emulsions.

The reaction products according to the invention can also be mixed with other demulsifiers, e.g. B. those based on alkoxylated Amines are used. It is also possible to use the polymers according to the invention mixed with organic solvent solvents, e.g. B. alcohols such. B. n-butanol, i-propanol, n- Propanol, n-butanol, s-butanol, t-butanol, octanols etc. preferred the percentage by weight of the alcohols is 2 to 10% by weight, based on the solids content of the mixtures.

The reaction products according to the invention show as demulsifiers in crude oil emulsions a high splitting speed and in their Very good reproducibility.

Examples 1. Polyetherols

In the following examples mean:

A1: Block copolymer of 1 mol of propylene glycol, reacted with (on average) 47.4 mol of propylene oxide, then with (on average) 20.0 mol of ethylene oxide (= example a3 from EP 264 841).
A2: Block copolymer from 1 mol of trimethylolpropane, reacted with (on average) 60.0 mol of propylene oxide, then with (on average) 10.0 mol of ethylene oxide (= example a5 from EP 264 841).
A3: Block copolymer from 1 mol of trimethylolpropane, reacted with (on average) 80.0 mol of propylene oxide, then with (on average) 30.3 mol of ethylene oxide (= example a15 from EP 264 841).

2. Preparation of the reaction products according to the invention General manufacturing instructions

II was mixed with 5.5 g of toluenesulfonic acid and at 100 ° C is heating. After adding a g of acrylic acid, the reaction mixture Maintained at this temperature for 1 h. Then at 90 ° C within 2.5 h I and at the same time b g t-butyl peroctanoate in c g solvent added. After one hour at 100 ° C 10 milky cloudy polymer solutions.

These polymer solutions were heated to boiling for 3.5 hours, with what ser was removed azeotropically. After cooling to room temperature the products were mixed with d g n-butanol and e g solvent puts.

The following tables 1 and 2 give quantities and starting materials, their molar and weight ratios as well as characteri data of the products.

Table 1

3. Comparative Example 1 (V1) (= Example B1 from EP 264 841)

A solution of 244 g of polyetherol A2 in 110 g of xylene was mixed with 4.8 g acrylic acid, 0.048 g hydroquinone monoethyl ether and 5 g p-To heated toluene sulfonic acid at 150 ° C for 5 h. 1.1 ml Water towed out. The acrylic acid ester thus obtained had one Residual acid number of 4.1. The acrylic acid ester solution thus prepared was mixed with 182 g of xylene and 43 g of acrylic acid and under Nitrogen atmosphere heated to 70 ° C. Was on within 2 hours finally a solution of 2.5 g in 85 g of xylene was added and there after another 1 h at this temperature. It was obtain a clear brown solution with a K value of 12.6. Now 2 h water removed azeotropically under reflux, abge to room temperature cools and mixed with 15 g of n-butanol. (Product V1)

Comparative Example 2 (V2) (= Example B14 from DE 41 04 610)

A solution of 342 g A3 in 126 g xylene was in the weak stick heated to 70 ° C and within 2 h a solution of 57.9 g acrylic acid and 14.5 g ethyl acrylate and one at the same time Solution of 1.45 g azobisisobutyronitrile in 50 g xylene evenly added. The mixture was then stirred at 70 ° C for one hour. Man received an oily, milky solution. This polymer solution was made with 1.9 g of p-toluenesulfonic acid were added and the mixture was boiled under reflux for 2 h river (140 ° C) heated. It was then cooled and 1.7 g Morpholine added. (Product V2)

4. Test of the demulsifier effectiveness

The demulsifier activity of the polymers according to the invention was based on a crude oil emulsion from the provincial Rühlermoor / Georgsdorf checked. For this purpose an active ingredient concentration was given tration of 8 ppm of the corresponding emulsion splitter, based to the solids content, while stirring the emulsion and the water separation in a measuring cylinder is tracked over time. The temperature of 50 ° C required for optimal emulsion splitting was thermostatted by setting the measuring cylinder Water bath reached. The numerical values given in the table correspond to the percentage of water split off, based on the total water content of the emulsion (= 100%).  

Table 3

Splitter effectiveness

The examples show that the demulsifiers according to the invention in at the same time lead to a much better separation of water ren as such according to the prior art.

Claims (7)

1. Suitable as demulsifiers for crude oil emulsions reaction products from olefinically unsaturated carboxylic acids and polyetholes, obtainable by

• A) condensation of one or more unsaturated C₃-C₁₀ carboxylic acids or their derivatives of the general formula I. in which R¹ and R² are hydrogen, C₁-C₄-alkyl or carboxyl and R³ is hydrogen or methyl, and R¹ can form a 5- or 6-membered hydride ring with the carboxyl group,
  with a polyetherol of the general formula II in the
  R⁴ for the remainder of a mono- or polyhydric alcohol, a phenol or an alkylphenol with 7 to 30 carbon atoms, the remainder of an alkylphenol / formaldehyde or alkylphenol / acetaldehyde condensation product,
  R⁵ for a branched or straight-chain C₂-C₄-alkylene group, where different units [R⁵-O] may be present within a polyalkylene oxide chain, and
  x represents an integer from 5 to 120,
  in the molar ratio of the compounds II to I from 2: 1 to 10: 1 and in the weight ratio from 25: 1 to 1000: 1,
• B) polymerizing the condensation product thus obtained with one or more unsaturated carboxylic acids I and optionally further olefinically unsaturated monomers which can be copolymerized with the carboxylic acids I, the proportion of carboxylic acids I in the amount of olefinically unsaturated monomers being 50 to 100 mol%, and where the molar ratio of polyetherol II to the sum of the olefinically unsaturated monomers used in process steps A) and B) is 1: 5 to 1: 200, and subsequent ones
• C) condensation of the reaction mixture thus obtained with the proviso that not all hydroxyl groups are reacted.

2. Reaction products according to claim 1, characterized in that that the olefinically unsaturated carboxylic acid I to 50 to 100 mol% consists of acrylic acid. 3. Reaction products according to claim 1 or 2, characterized records that the rest R⁵ stands for ethylene and propylene. 4. Mixtures containing 30 to 60% by weight of reaction products according to claims 1 to 3, an organic solvent such as other demulsifiers if necessary. 5. Process for the preparation of the reaction products according to claim 1, characterized in that

• A) one or more unsaturated C₃-C₁₀ carboxylic acids or their derivatives of the general formula I. in which R¹ and R² are hydrogen, C₁-C₄-alkyl or carboxyl and R³ is hydrogen or methyl, and R¹ can form a 5- or 6-membered hydride ring with the carboxyl group,
  with a polyetherol of the general formula II in the
  R⁴ for the residues of a mono- or polyhydric alcohol, a phenol or an alkylphenol with 7 to 30 carbon atoms, the rest of an alkylphenol / formaldehyde or alkylphenol / acetaldehyde condensation product,
  R⁵ for a branched or straight-chain C₂-C₄-alkylene group, where different units [R⁵-O] may be present within a polyalkylene oxide chain, and
  x represents an integer from 5 to 120,
  condensed in the molar ratio of the compounds II to I from 2: 1 to 10: 1 and in the weight ratio from 25: 1 to 1000: 1,
• B) the condensation product thus obtained is polymerized with one or more unsaturated carboxylic acids I and, if appropriate, further olefinically unsaturated monomers which can be copolymerized with the carboxylic acids I, the proportion of the carboxylic acids I in the amount of the olefinically unsaturated monomers being 50 to 100 mol%, and then the molar ratio of polyetherol II to the sum of the olefinically unsaturated monomers used in process steps A) and B) is 1: 5 to 1: 200, and then
• C) the reaction mixture thus obtained condensed with the proviso that not all hydroxyl groups are reacted.

6. Use of the reaction products according to claims 1 to 3 as demulsifiers for crude oil emulsions. 7. Use of the mixtures according to claim 4 as demulsifiers for crude oil emulsions.